| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1985: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1984: ¥400,000 (Direct Cost: ¥400,000)
|
|---|
| Research Abstract |
The Laves phase compounds have the three types of crystal structures: hexagonal C14 and C36 and cubic C15. The more than 200 with these structures compounds have been found. The magnetism are full of variety, which has not been observed in the other compounds. The aid of this project is to investigate the relation between the magnetism and electronic structures. The following results have been obtained.
(1) Band calculations were carried out for the compounds between transition metals and the density-of-states (DOS) and the magnetic moments were obtained. We can guess the magnetism (para, ferro or antiferromagnetism) from the position of the Fermi level in the paramagnetic DOS.
(2) The crystal structure of Laves compounds A <B_2> is mainly determined by the B atom: the crystal structure is the C14 type when the B atom is Cr, Co or Ni (Mo, Rh or Pd) and the C15 structure when the B atom is Mn or Fe (Tc or Ru). The magnetism is concerned with the structure when this rule cannot be applied.
(3) The band width of the B atom changes delicately by the A atom. When the A atom changes in the order Y, Zr, Nb that is, the magnetism of the B atom becomes strong in the order Nb, Zr, Y.
(4) The same tendency is seen when the atom is substituted from a 4d transition metal to a 3d transition metal. The band width of the B atom is widened. Therefore, the enegy gain due to the spin polarization decreases and Ti <Fe_2> exhibits antiferromagnetism although Zr <Fe_2> exhibits ferromagnetism.
|
